Effects of loci determining photoperiod sensitivity (Ppd-H1) and vernalization response (Sh2) on agronomic traits in the 'Dicktoo' x 'Morex' barley mapping population
I. Karsai et al., Effects of loci determining photoperiod sensitivity (Ppd-H1) and vernalization response (Sh2) on agronomic traits in the 'Dicktoo' x 'Morex' barley mapping population, PLANT BREED, 118(5), 1999, pp. 399-403
The objectives of this research were to determine the individual and intera
ction effects of the Ppd-H1 and Sh2 loci on agronomic traits under short- a
nd long-photoperiod regimes. Nineteen doubled haploid (DH) lines from the '
Dicktoo' x 'Morex' mapping population, which represented the four genotypes
at the Ppd-H1 and Sh2 loci, were phenotyped in controlled environment phot
operiods. Both Ppd-H1 and Sh2 had significant effects on several agronomic
traits, in addition to their role in determining first node appearance and
flowering time. The magnitude of these effects depended on daylight. Under
long-day conditions (18 h) Ppd-H1, and under short-day conditions (12 h) Sh
2 was a significant determinant of most characters. The interactions betwee
n these two loci were significant for several characters, particularly for
yield components, under both long- and short-photoperiod regimes. Under the
long-day treatment, Ppd-H1 influenced plant height: through the determinat
ion of node number. There was an epistatic association between the two loci
for both 1000-kernel weight and tillering. The combination of photoperiod
insensitivity and vernalization requirement caused a significant increase i
n tillering. This was paralleled by a decrease in 1000-kernel weight. Under
the long-day treatment, neither Ppd-H1 nor Sh2 influenced plant yield. Und
er short-day conditions, the combination of photoperiod insensitivity and v
ernalization requirement had a pronounced negative effect on plant yield.